The advantages of a flexible rising main in beach wells

Abstract

Angus Flexible Pipelines is the industrial hose division of Kidde plc — a major FTSE200 British company — manufacturing a range of long-length layflat hoses for use in potable water and general bulk liquid transfer applications. These include Wellmaster Flexible Rising Main, which is designed to replace steel pipes with submersible pumps in boreholes. The selection of appropriate materials throughout the desalination process is critical for cost-effective, longterm operation of plants. In addition to the economic considerations of a long efficient service life, as the provider of a life-sustaining service, it is essential that interruptions to operations be kept to an absolute minimum. The concept of Flexible Rising Mains was developed over 20 years ago and they are in use throughout the world in applications where water is abstracted from boreholes. Their all-synthetic construction makes them particularly attractive to operators of reverse osmosis plants where the water intake is from beach wells using submersible pumps. Features of Flexible Rising Mains include: • Totally unaffected by high salinity. No corrosion. • No scaling • No flanges or joints except at the pump and wellhead. • Hydraulically more efficient than steel or GRP pipe. • Light and compact. Benefits to the user as a result include: • Long service life. • No deterioration in hydraulic performance over time. No scaling which can detach and damage the membrane. • Rapid installation and retrieval of the submersible pump. Minimum downtime for maintenance or repair, with minimum interruption of supply. • This benefit can be taken as power savings, smaller pump for the same flow or smaller diameter riser. • Easy to store and transport — particularly relevant in remote areas. They require less heavy-duty plant (trailers and cranes) and smaller work crews. A technology that has been used extensively in other areas of the water market for many years has been growing strongly in the desalination sector for the past 7 years. The paper will seek to fully detail the concept and to expand on the features and benefits relevant for operators of reverse osmosis desalination plants.